Quality compressed air is the life blood of the manufacturing industry and approximately 70% of all manufacturers have a compressed air system to drive a variety of equipment. The generation of compressed air is one of the highest consumers of energy, accounting for over 40% of a manufacturing plant’s total electricity bill. Energy is thus the most expensive component in the total cost of compressed air, often costing several times more than the purchase price of the compressor over its lifespan. But alongside energy, there are many other elements that determine a compressor’s efficiency and that add to the cost of producing compressed air such as pressure, flow, air quality, maintenance and service procedures as well as the delivery system (piping). “The right pressure for the application, the right product for that pressure, the right air quality, the right delivery system and finally the right timing for maintenance and service. With a few simple calculations and checks compressor efficiency will be optimised, costs will be reduced and the bottom line will be boosted,” according to Atlas Copco Compressor Technique Business Line Managers, Charl Ackerman (Industrial Air), Pieter van Wyk (Oil-free Air) and Ian Ainsworth (Service). Atlas Copco understands the relentless pursuit by mining and industry to minimise operational expenses and optimise productivity and efficiency for sustainable profitability. Efficiency is thus integral to the design of Atlas Copco’s air, gas and vacuum compressor technology and systems. “Small, medium and large compressors, oil-free and oil injected, filters, dryers and piping - we offer world-class quality, end-to-end air solutions that address efficiencies across all the elements - energy consumption, operating pressures, flow rates, air quality, delivery systems and service.” The journey to compressor efficiency starts with the analysis of the customer’s compressed air demand profile to determine the correct compressor size for the application. Over- or under-sizing will lead to inefficient compressed air supply.
Variable Speed Drive (VSD) presents the best solution for applications where air demand fluctuates and where the compressor is regularly run at below maximum capacity. While a traditional fixed speed compressor is either on or off, a VSD compressor automatically adjusts its motor and element speed to the air demand. As it only runs at the required speed, the VSD compressor delivers significant cuts in energy consumption and subsequent costs. With Atlas Copco’s latest ground-breaking VSD+ technology, a manufacturing plant can cut its energy bill in half!
A fixed speed compressor is recommended by Atlas Copco as the most efficient solution for applications that demand constant pressure or applications requiring air at maximum capacity 24/7.
The next step is to ensure that the pressure is correct for the application. Certain tools like welders and laser cutters perform optimally at the right pressure; incorrect pressure (too high or too low) will compromise end-product quality. The compressor must produce air at a pressure high enough to overcome pressure losses in the supply system while still meeting the minimum operating pressure of the end-use equipment. If pressure loss is greater than 10% (pressure loss in a properly designed system will be less than 10% of the compressor’s discharge pressure) Atlas Copco recommends evaluation to identify areas causing excessive pressure drops. It can be something as simple as condensation drains not operating properly or leakage in the pipework.
Air treatment is the next important consideration on the road to efficiency. Quality compressed air demands quality dryers and filters. “All compressed air, regardless of humidity or dryness of ambient atmosphere, emerges from a compressor 100% saturated,” states van Wyk. “Upwards of 95% of compressors require a dryer of some description to prevent corrosion of tools and equipment. Unfortunately, unless there is a specific need or a critical application, a dryer is often at the bottom of the shopping list when compressed air installations are considered. We offer a wide range of in-house manufactured dryers for optimum air quality.” To minimise energy losses normally associated with compressed air filtration, it is critical that the filter design combines maximum contaminant removal efficiency with minimum pressure drop.
Atlas Copco’s patent-pending UD+ cartridge filter solution delivers a 40% lower pressure drop and removes contamination in compressed air down to 0.01 ppm from a single filter unit. As much as 90% of the electrical energy used by a compressed air solution is converted into heat. Up to ± 75% of this heat can be recovered as hot air or hot water with Atlas Copco’s state-of-the-art energy recovery system. Re-using the heat generated in the compressor (that would otherwise be wasted) to run hot water showers in a production facility for example, delivers substantial energy savings. On-site industrial gas (nitrogen and oxygen) generation offers a more sustainable and cost-efficient solution than cylinder or bulk liquid supply which requires transport, handling and resulting administration. “An on-site nitrogen generator such as the Atlas Copco NGP+ with PSA (Pressure Swing Adsorption) technology can simply be plugged into an existing compressed air installation to offer an independent, reliable and flexible supply of nitrogen with purities of up to 99,999%,” affirms Ackerman.
The supply of ultra clean medical air to theatres and hospital beds is a vital life support service and Atlas Copco offers turnkey ISO 7396-1 accredited medical gas products and systems to the health industry. Almost at the end of the air compressor journey is the distribution network or piping. “The correct sizing of pipe work is critical,” notes Ainsworth. “Increasing the size of a pipe can reduce pressure drop by up to 50% and by shortening the distance air has to travel can further reduce pressure drops by about 20 to 40%.” As a faulty distribution system and air leaks can cause pressure loss, we highly recommend routine checks.”
Atlas Copco’s AIRnet piping system optimises the transfer of compressed air at the desired flow and pressure to the point of use. The last leg of the journey in the pursuit of optimum compressor efficiency is exemplary after-market service and preventative maintenance. No matter how exceptional the quality of the compressor, inferior service by untrained technicians, using the wrong tooling or incorrect parts or incorrect fitting can lead to inefficient performance and even critical failure. “By leaving service and repair in the capable hands of qualified Original Equipment Manufacturers (OEMs) can result in savings up to 25% of the current cost to run the compressed air system,” affirms Ainsworth. “When it comes to quality air solutions, we have no favourites because we have the total quality air technology solution covered. From under the Atlas Copco banner we are able to give customers exactly what they need to ensure the sustainable productivity and ultimate profitability of their plant.”